April: Customer Spotlight: Vitek Legacy to Vitek 2
East Jefferson General Hospital
As supervisor of the microbiology laboratory at East Jefferson General Hospital in Metairie, Louisiana, I am responsible for workflow and staffing of the microbiologists who prepare and read bacterial cultures from hospital patient samples.
When I first came to East Jefferson General Hospital in 1990, the lab already had VITEK® Legacy system. It was the workhorse of our microbiology laboratory. At the time, it was one of the most powerful instruments available to microbiologists for identifying bacterial pathogens and testing bacterial susceptibility to known antibiotics. We pushed our VITEK Legacy it to its outer limits and it always responded well.
The VITEK Legacy had certain inherent problems with regard to workflow and sample processing. Most of the steps had to be performed manually, which placed an enormous burden on my staff. We had to prepare each Identification and Antibiotic Susceptibility Testing (ID/AST) manually. That meant physically picking each colony off the incubation plate, dispensing saline into each ID and AST tube, and inoculating each ID tube. Furthermore, we had to incubate each ID tube, zero and check the colorimeter, standardize the ID inoculums in the colorimeter, and adjust the inoculums if the McF was too high or too low. There were so many steps involved that we were lucky if we could process ten samples at a time.
Once we completed the ID/AST steps, the real work began. We had to setup the VITEK Legacy and ID cards, which meant manually writing the accession numbers on each unique card using a Sharpie pen—a method could potentially turn into a nightmare quickly. Manually writing accession numbers also increased the reader error rate because the VITEK Legacy couldn't always read the numbers clearly. When that happened, the wrong accession numbers could be logged into the reader or, in some instances, the reader couldn't decipher the numbers at all.
We had to insert a straw in each ID and AST card before placing them in a cassette with other ID and AST cards. Each ID card was placed in an ID suspension and each AST card was placed in an AST suspension. The cassette was then loaded into a vacuum chamber that would draw the suspension into the cards. When the cards were filled, we had to remove them from the vacuum chamber and use the sealing chamber to cut and seal the end of each straw to prevent contamination. Finally, we loaded the card into the reader and obtained the result. Once we obtained the results, each card was removed manually from the reader incubator and placed in a biohazard container... The entire process was time and labor intensive and, because of the number of manual steps performed, there was a greater likelihood of introduced error.
A few years ago, we started having problems with our Vitek Legacy. After nearly 20 years of solid performance, it started to have a significant number of hardware issues that resulted in very extensive and expensive repairs. On top of that, we didn't have a service contract, so we had to pay for those repairs out of our laboratory budget.
I'd tried for a few years to get the hospital to upgrade to the new VITEK® 2 XL. The hospital, however, was reluctant to commit to such a large capital expenditure. bioMérieux knew how important our VITEK system was to the operation of our laboratory, so they worked with us to create a financial package that fit our budget. Best of all, they included a preventive maintenance and support package so we didn't have to pay for anymore out-of-pocket repairs.
The VITEK 2 XL has dramatically changed how we process microbiology samples. The new systems is fully automated, so virtually all of the manually intensive steps have been eliminated. It also significantly reduced the amount of hands-on time my lab techs had to spend processing a sample, so we saw a large increase in efficiency. All we do now is grow the initial colonies overnight and pick the colonies to saline using turbidities based on the organism type.
Once the primary isolation is complete, there is minimal handling required. The standardized inoculum is placed in a cassette and a specimen identification number is automatically entered into the Smart Carrier Station™. A hand-held scanner reads the barcode directly from specimen ID so greater traceability of the patient sample. In addition, the Smart Carrier Station reduced the amount of time that microbiologists handle the organism suspensions linking the specimen to the test card.
After we load the samples into the VITEK® 2 XL, the instrument takes over and does the rest, We no longer have to manually enter the accession numbers or make the dilutions for susceptibility panels. The instrument cuts the straws and places the cards in the reading chamber. Another critical component of VITEK 2 technology is the Advanced Expert System™ (AES).
As any microbiologist knows, it's very difficult to keep track of all the phenotypes and MIC distributions for microbiological pathogens. More than 100 antibiotics are available for testing aerobic bacteria and fastidious organisms. That's why it so important to have quantitative MIC data when managing critical infections such as sepsis in critical care patients.
AES automatically analyzes MIC patterns and detects phenotypes for most organisms, providing accurate "fingerprint" recognition of bacterial resistance mechanisms. Phenotype identification and resistance detection footprints also are an important part of identifying various bacterial strains and susceptibility profiles. The VITEK 2 AES knowledge base was created from more than 100,000 references. Once a sample is read, the AES compares it to more than 2,000 described phenotypes and Minimum Inhibitory Concentration (MIC) distributions. AES can detect as many as 100 resistance mechanisms in more than 99 organisms, and it has a resulting range of five to seven MIC doubling dilutions per antibiotic with an extended MIC range that enables low-level resistance detection.
We also use Etest® as a backup for antimicrobial resistance testing, particularly in situations where on-scale MICs are needed to make treatment decisions. In today's cost conscious healthcare environment, Etest provides a cost-effective tool for generating MICs across 15 dilutions. It also provides a macromethod format for optimizing resistance detection. That means that clinicians can start targeted therapies sooner, thereby improving patient outcomes and enhancing antibiotic stewardship.
Our VITEK® 2 expert system can identify the correct susceptibility profile nearly 100 percent of the time. In the event it detects a questionable strain or an unknown strain, it flags the card so that a microbiologist can review it and make the final identification.
The VITEK 2 has reduced our technologist time by as much as 75%. Where my technologists used to sit at a bench all afternoon preparing cards, inoculating samples, and comparing susceptibility profiles, they now just insert the saline sample and the instrument does the rest. The VITEK 2 XL has changed how my laboratory handles microbiological samples. And, it's all for the better.
The VITEK® 2 has had a dramatic effect on our daily routines.
- The Advanced Expert System™ automatically analyzes MIC patterns and detects phenotypes for most organisms and detect as many as 100 resistance mechanisms in more than 99 organisms
- Etest® generates MICs across 15 dilutions.
- The Smart Carrier automatic scanning feature reduces errors associated with Sharpie notation
- Increased the accuracy, reliability, and reproducibility of microbiology samples
- Fewer sample handling errors
- Better quality control because there are fewer manual steps
- Elimination of workflow barriers that are associated with manual sample processing
- Reduced technologist time by as much as 75%
- Better staff utilization